import java.util.Scanner; // 注意类名必须为 Main, 不要有任何 package xxx 信息 public class Main { public static void main(String[] args) { Scanner in = new Scanner(System.in); String str = in.nextLine(); char[] chars = str.toCharArray(); for (int i = 0; i < chars.length - 1; i++) { for (int j = 0; j < chars.length - i - 1; j++) { if (chars[j] > chars[j + 1]) { char temp = chars[j + 1]; chars[j + 1] = chars[j]; chars[j] = temp; } } } for (char c : chars) { System.out.print(c); } } }